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How to get rid of mold spores in the air

Five easy steps to get rid of mold spores in the air
Updated on January 24, 2024
Written by
Danny Ashton
Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.

So, if you’ve noticed a few mold patches in your home, don’t panic.

Mold spores are a common type of airborne biological pollutant found in homes throughout the U.S. They can find their way in through open doors and windows, and they can also travel by clinging to your clothing or shoes. Though these spores are tiny (only about 2 – 100 microns), they can quickly grow into thriving colonies. 

Worryingly, several types of indoor mold can significantly impact your health, causing breathing troubles and rashes.

In this guide, we will help you avoid these issues by exploring how to get rid of mold spores — for good!

  • A World Health Organization review found that dampness is estimated to be present in 20-50% of homes in the US, which is a major risk factor for mold.
  • The WHO also concluded that dampness and mold are associated with almost a 30-50% increase in rates of respiratory illnesses.
  • A study by the EPA estimated about 4.6 million cases of asthma in the US are directly caused by mold.
  • The WHO found that asthma-related symptoms like coughs or wheezing are reduced by 25-45% when mold environments are improved.
  • A Mayo Clinic study found that 96% of patients with chronic sinus infections have them as a direct result of overexposure to mold.
  • A study found that the total annual cost to society attributable to dampness and mold is estimated to be $3.7 billion for allergic rhinitis, $1.9 billion for acute bronchitis, $15.1 billion for asthma morbidity, and $1.7 billion for asthma mortality.

5 ways to prevent mold spores in the air

Those statistics have shown how damaging mold can be, both for your health and for your home. So, what can you do to stop it from getting to the stage where you need to call out the experts or start noticing health problems caused by the spores? Here are five easy steps to help prevent mold from growing and affecting the air quality in your home.

1. Shut doors and windows

Starting off with the simplest method for preventing mold in the first place, keeping your doors and windows closed as much as possible as this is the main way mold can get in your home.

The Environmental Health and Safety department of the University of Washington advises its staff and students: “Doors left open can increase the relative humidity in the room and promote mold growth. Maintaining relative humidity at less than 60% helps to discourage mold growth.”


Take the time to clean mold off windows:

  1. Spray the affected area with a bleach solution of no more than 1 cup of household laundry bleach in 1 gallon of water
  2. Gently wipe away the mold
  3. Soak the area with bleach
  4. Use a clean dry cloth to dry the area

2. Keep your home dry

A dry home is much less likely to develop mold. The EPA says, “The key to mold control is moisture control.” Because mold is a type of fungus, it grows in damp places, which is why it’s most often found in bathrooms, kitchens, and basements. So, keeping your home as dry as possible is essential for mold prevention.


The United States Environmental Protection Agency recommends the following measures:

  • Fix leaks and seepage
  • Put a plastic cover over dirt in the crawl space
  • Use exhaust fans in bathrooms and kitchens
  • Use storm windows and insulation to raise the temperature of cold surfaces where moisture condenses

3. Keep your home well-ventilated

Ventilation is another key way to ensure that mold does not have the environment it needs to grow and is better for your health in general, particularly during the COVID-19 pandemic. This means ensuring clean air is flowing through your home, and there are plenty of ways you can achieve this, including using an HVAC system with an air conditioning unit and a filter.


Fans can be useful for improving ventilation throughout your home. You should:

  • Use an exhaust fan in your bathroom and leave it on for half an hour after using the shower
  • Run ceiling fans in the kitchen while cooking
  • Install fans in your attic 
  • Make sure other fans do not vent into the attic, but vent outside your home.
  • Install ceiling fans in your basement, especially if there are no windows.

4. Get a dehumidifier

A dehumidifier is a device that removes moisture from the air. It works by sucking in air, removing the excess moisture, then pushing it out again. Any humidity lingering in the air condenses into water droplets during this process. You can maximize your dehumidifier’s effectiveness by placing it in high-humidity areas. Bathrooms and kitchens are a great place to start.


When choosing a dehumidifier, there are three main factors to consider:

  • What size room are you using it in?
  • How much moisture is in the air?
  • Do you need one with a reservoir or a continuous drain?

5. Use an air purifier

Installing an air purifier is the next step toward cleaner, mold-free interior air. Much like a dehumidifier, an air purifier pulls in air. However, instead of cooling this air, an air purifier pushes it through a fine filter.

This filter can remove common airborne contaminants, including mold. Air purifiers for mold come in several sizes and types. Here at HouseFresh, we recommend investing only in units that use HEPA and activated carbon filters. Finding the right purifier depends on the size of the space you’re using it in and the severity of the problem.


Choose the best air purifier depending on the room and follow these guidelines:

  • Bathroom: The lack of ventilation in most bathrooms + the warmth + high levels of moisture = make mold and mildew a real problem. An air purifier with a true HEPA/H13 filter will capture a greater number of airborne particles, while one with activated carbon or charcoal will help to eradicate unwanted bathroom smells (you know what we mean).
  • Kitchen: From last night’s cooking to the acrid smell of cleaning products, there are many odors polluting the air in the kitchen. This means you need a purifier with HEPA and Activated Carbon filtration to capture the airborne particles and smells, giving you a fresh and clean-smelling room.
  • Basement/Attic: Whether you’re using them for storage or as living spaces, basements and attics need purifiers that can tackle the size of the room and improve the air quality, which can be badly affected by poor ventilation. A dehumidifier could also be needed if you have issues with damp in the basement.

How to clean moldy areas

Cleaning moldy areas can be daunting, as mold can grow on surfaces you might not otherwise clean very often. But don’t worry, we’re here with step-by-step instructions. Also, be sure to check out what we think is the best mold killing paint as this can be used once mold has been removed. Check out our infographic to find out how to solve the mold problems around your home:

When you should call mold remediation services

Mold growth is often hidden, a quality that can make it challenging to eliminate. However, a handful of red flags may indicate mold growth.

Some of the most common signs of mold growth include:

  • An earthy smell that permeates the home
  • Peeling drywall or ceiling paint
  • Unexplained skin rashes
  • Difficulty breathing when indoors
  • Colored spots on tiles, walls, or flooring

If you notice any of the above symptoms, you may have a mold problem on your hands. You can treat small colonies at home with a mixture of bleach and water. However, widespread mold colonies require professional services.


Mold remediation costs vary, but the average price is about $2,000. If the mold growth has spread or eaten through drywall, you’ll also need to add repair costs to this number. Because mold removal and repair services are pricey, it’s often better to prevent mold growth rather than treat it.

Bathroom$500 – $1833
Crawl Space$500 – $1833
Basement$833 – $3167
Attic$1000 – $4833
Drywall$1000 – $13500
Concrete Walls$1100 – $7000
Air Ducts$1900 – $6500
Whole House$11667 – $30000
Roof Leak$413 – $1150
Leaking Pipe$45 – $150 per hour
Mold inspections$332 – $803
Mold testing kit$14 – $45

The importance of preventing indoor mold growth in the first place

We’ve shown you everything you need to know about removing mold spores in the air, but the easiest way to deal with mold is to prevent it from happening in the first place. 

Air purifiers and dehumidifiers are ideal for removing mold spores and the moisture that can cause mold. Combine these devices with the tips we’ve given, and you can prevent mold from growing in the key problem areas of your home.

Not taking any action can lead to health issues, leave lasting structural damage to your home and destroy your possessions. This can all be avoided by following our simple tips and investing in a dehumidifier or air purifier.

About the author

Danny Ashton

Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.